Viscometers for measuring viscosity of a fluid are generally classified according to basic principles into a capillary viscometer, a falling sphere viscometer, a rotational viscometer, a chemical viscometer, and an oscillating viscometer.
Of these types of viscometers, in JP 2004-361300 A, for example, there is proposed a oscillating viscometer for calculating viscosity of a measured object based on a driving current generated due to an inductor plate being electromagnetically oscillating with a predetermined amplitude, or there is proposed a oscillating viscometer for calculating viscosity of the same by making an oscillating body externally excite, obtaining a frequency response curve representing relationship between excitation frequency and corresponding response amplitude of the oscillating body, and finding a Q value thereof.